TAILORING THE PERFORMANCE OF SPECIALTY POLYOLEFIN ELASTOMER BASED ELASTIC NONWOVEN FABRICS

摘要

Specialty Polyolefin Elastomers (SPE) are a new generation of metallocene catalyst based polyolefins that can be processed in conventional spunmelt equipment to produce elastic nonwoven fabrics. The elastic nonwoven can be used in several applications such as personal care, adult incontinence, medical and industrial applications. SPE grades of varying melt flow rate have been developed for both spunbond and meltblown processes. This paper examines properties of spunbond nonwoven fabrics comprising in-line blends of an SPE resin and an isotactic polypropylene (PP), over a wide range of SPE to PP blend ratios. The SPE polymer selected for this study is a 80 MFR spunbond grade, while the isotactic PP is a 36 MFR commercial polymer used extensively in spunbond applications. The processability of SPE is very similar to that of conventional polyolefins such as PP. At varying blend ratios of SPE to PP, fabric samples were made with changes in draw force and calender bonding temperature. Fiber diameter is affected by the addition of PP at constant draw force, or by varying the draw force at fixed SPE/PP ratio, both of which influence the tensile and elastic properties of the nonwoven fabric. The effect of increasing bonding temperature from 75 °C to 125 °C in both SPE and SPE/PP blends, diminishes tensile strength and elongation suggesting an optimum, while minimum bonding pressure is favored for achieving the highest physical properties, within the blend ratio investigated in this study. Non linear regression models were constructed to correlate the change in physical properties with factors such as SPE/PP blend ratio, draw force, and calender temperature and fabric basis weight. The feel/ "hand" properties of the fabric are also effectively tailored by addition of PP, however at the expense of elastic performance.